Abraham Lincoln is on the 5 dollar bill and the shirt is about greed so he represents money (I assume).

To tie both countries in you could have a red oval or circle behind Abe to look like the 5 dollar bill,which would represent both the dollar and Japanese flag and maybe add a little banner over the top or bottom just like the dollar that says greed in English and keep Kanji where it is or just put it on the banner instead . Either way, I like the concept and the design.